A Simplified Model To Predict the Effect of Increasing Atmospheric CO2 on Carbonate Chemistry in the OceanBrian J. Bozlee, Maria Janebo, and Ginger JahnThe chemistry of dissolved inorganic carbon in seawater is reviewed and used to predict the potential effect of rising levels of carbon dioxide in the atmosphere. It is found that calcium carbonate may become unsaturated in cold surface seawater by the year 2100, resulting in the destruction of calcifying organisms such as coral.Bozlee, Brian J.; Janebo, Maria; Jahn, Ginger. J. Chem. Educ.2008, 85, 213.

Applications of Chemistry |

Aqueous Solution Chemistry |

Atmospheric Chemistry |

Equilibrium |

Green Chemistry |

Water / Water Chemistry

Experimental Determination of Ultraviolet Radiation Protection of Common MaterialsSusana C. A. Tavares, Joaquim C. G. Esteves de Silva, and João PaivaThe oxidation of iodide is used as an indicator for the degree of exposure to UV radiation and to investigate the protection given by a simulation of ozone using plexiglass plates, sunscreen lotions, cotton cloth with different colors, and aqueous solutions with different concentrations of natural organic matter.Tavares, Susana C. A.; Esteves de Silva, Joaquim C. G.; Paiva, João. J. Chem. Educ.2007, 84, 1963.

Geographical Information Systems (GIS) Mapping of Environmental Samples across College CampusesKathleen L. Purvis-Roberts, Harriet P. Moeur, and Andrew ZanellaIn this laboratory experiment, students take environmental samples (concentrations of nitrogen dioxide) and geospatial coordinates with a global position systems unit at various locations around campus, map their data on a geo-referenced map with geographical information systems software, and compare their results to those observed by governmental agencies.Purvis-Roberts, Kathleen L.; Moeur, Harriet P.; Zanella, Andrew. J. Chem. Educ.2007, 84, 1691.

Applications of Chemistry |

Atmospheric Chemistry |

Gases |

Laboratory Computing / Interfacing |

UV-Vis Spectroscopy

A Simple Calorimetric Experiment That Highlights Aspects of Global Heat Retention and Global WarmingJoel D. Burley and Harold S. JohnstonIn this laboratory experiment, general chemistry students verify that heat is consumed in the melting of ice, with no increase in temperature until all the ice has melted. The fundamental calorimetric principles demonstrated by the lab results are then developed to help students better assess and understand the experimental evidence associated with global warming.Burley, Joel D.; Johnston, Harold S. J. Chem. Educ.2007, 84, 1686.

Atmospheric Chemistry |

Calorimetry / Thermochemistry

Lewis Structure Representation of Free Radicals Similar to ClOWarren Hirsch and Mark KobrakAn unconventional Lewis structure is proposed to explain the properties of the free radical ClO and a series of its isoelectronic analogues, particularly trends in the spin density of these species. Hirsch, Warren; Kobrak, Mark. J. Chem. Educ.2007, 84, 1360.

Atmospheric Chemistry |

Computational Chemistry |

Covalent Bonding |

Free Radicals |

Lewis Structures |

Molecular Modeling |

MO Theory |

Valence Bond Theory

Guitar Strings as Standing Waves: A DemonstrationMichael DavisThis demonstration uses an acoustic guitar to produce three unique harmonic vibrations, each of which is representative of a standing wave and illustrates the concept of quantization.Davis, Michael. J. Chem. Educ.2007, 84, 1287.

Response to "Keeping Our Cool"Roy W. ClarkGeneral chemistry teachers should teach general chemistry. They should teach neither the appreciation of the wonders of modern science, nor should they teach the evil consequences of modern science.Clark, Roy W. J. Chem. Educ.2007, 84, 232.

Steel Wool and Oxygen: A Look at KineticsJames Gordon and Katherine ChanceyAn experimental method is described to study the kinetics of the reaction of the iron in steel wool with molecular oxygen. A calculator-based data collection system is used with an oxygen gas sensor to determine the order of the reaction with respect to oxygen. Using the graphical method, students determine that the reaction follows first-order kinetics with respect to oxygen. Gordon, James; Chancey, Katherine. J. Chem. Educ.2005, 82, 1065.

Atmospheric Chemistry |

Gases |

Kinetics |

Oxidation / Reduction

Greenhouse Gases and Non-gray BehaviorJ. C. JonesGreenhouse gases feature in many courses in applied chemistry as well as in courses on environmental science, atmospheric chemistry, and so on. We hear a great deal about such matters from the media. A more classical topic which first-year chemistry students will learn about in the physical chemistry component of their program is the black body concept and the StefanBoltzmann law. Recently in teaching about greenhouse gases to MSc students I have thought of a link between the topical and classical matters that is pedagogically interesting and might be of value to others teaching in this subject area.Jones, J. C. J. Chem. Educ.2005, 82, 837.

Atmospheric Chemistry |

Gases

The Determination of the Percent of Oxygen in Air Using a Gas Pressure SensorJames Gordon and Katherine ChanceyA new detection method is applied to a classic experiment in which gaseous atmospheric oxygen in a test tube is reacted with the iron in steel wool to produce rust. A gas pressure sensor interfaced to a calculator-based data collection system was used to measure the percent of oxygen in the air as the reaction proceeded. The results from the calculator-based experiment were compared to the results from a more traditional water-measurement experiment. The average percent of oxygen obtained using the calculator system was 19.4  0.4%. Gordon, James; Chancey, Katherine. J. Chem. Educ.2005, 82, 286.

Atmospheric Chemistry |

Gases |

Oxidation / Reduction |

Reactions

Fractional Distillation of Air and Other Demonstrations with Condensed GasesMaria Oliver-Hoyo and William L. Switzer, IIIThis demonstration builds upon the commonly performed liquefaction of air not only to show the presence of nitrogen and oxygen, but also the presence of two other components, carbon dioxide and water. Several extensions are suggested: one to show boiling point elevation in solution and another to show the elevation of both boiling point and sublimation point with pressure. No special apparatus is required permitting presentations to audiences in a variety of settings. These demonstrations give the opportunity to discuss properties of gases, solution chemistry, and phase equilibria.Oliver-Hoyo, Maria; Switzer, William L., III. J. Chem. Educ.2005, 82, 251.

Gases |

Qualitative Analysis |

Atmospheric Chemistry |

Phases / Phase Transitions / Diagrams |

Separation Science

On the Buoyancy of a Helium-Filled BalloonJohn E. HarrimanIt is shown by expansion of the exponential in the barometric formula that the forces due to pressure acting on a balloon are of the form (PV/RT)Mg and that results agree with those suggested by Archimedes principle. Einstein's equivalence principal provides an answer to what balloons will do in an accelerated car. Harriman, John E. J. Chem. Educ.2005, 82, 246.

Atmospheric Chemistry |

Gases |

Kinetic-Molecular Theory |

Physical Properties

Water in the AtmosphereJoel M. KauffmanNone of eight college-level general chemistry texts gave a mean value for water in the atmosphere, despite its being the third most prevalent constituent at about 1.5% by mass as vapor and about 2% if clouds and ice crystals are included. The importance of water as a greenhouse gas was omitted or marginalized by five of the eight texts. An infrared spectrum of humid air was determined to demonstrate that water vapor, because of its higher concentration, was more absorptive than carbon dioxide. The cooling effect of clouds, or other influences on the Earth's albedo, were not mentioned in most of the texts. These pervasive errors should be corrected in new or future editions of textbooks. Kauffman, Joel M. J. Chem. Educ.2004, 81, 1229.

Atmospheric Chemistry |

Gases |

Green Chemistry |

IR Spectroscopy

Mass Spectrometry for the MassesJared D. Persinger, Geoffrey C. Hoops, and Michael J. SamideIn this article, we describe an experiment for an introductory chemistry course that incorporates the use of mass spectrometry for sample analysis. Several different air samples are collected that represent various chemical processes, and the composition of the air sample is predicted on the basis of known chemical principles. A gas chromatograph-mass spectrometer is used to analyze these samples, and the relative quantities of nitrogen, oxygen, carbon dioxide, water, and argon are calculated. On the basis of the data, the hypothesized sample composition is validated. Persinger, Jared D.; Hoops, Geoffrey C.; Samide, Michael J. J. Chem. Educ.2004, 81, 1169.

Mass Spectrometry |

Atmospheric Chemistry |

Green Chemistry |

Nonmajor Courses |

Oxidation / Reduction |

Photosynthesis |

Gases

Why Does a Helium-Filled Balloon "Rise"?Richard W. RametteThe article is a lighthearted, conversational exploration of the microscopic basis for Archimedes principle. The principle is discussed in terms of molecular collisions and density gradients in a gravitational field. Ramette, Richard W. J. Chem. Educ.2003, 80, 1149.

A Novel Experiment for Fast and Simple Determination of the Oxygen Content in the AirMetodija Najdoski and Vladimir M. PetrusevskiThe reaction between nitric oxide (NO) and oxygen is used for determination of the oxygen content in the air. The nitrogen dioxide thus produced is dissolved in water. The volume decrease of the gas enables quick and accurate enough determination of the O2 content. The results of 20 measurements give %O2 = 21.04  0.63. Najdoski, Metodija; Petrusevski, Vladimir M. J. Chem. Educ.2000, 77, 1447.

Relative HumidityR. Bruce MartinDaily we hear reports of relative humidity, yet most students remain unfamiliar with its import. This short article defines and describes the concept at several levels. A new, general interest, isobaric plot directly indicates the dependence of relative humidity on temperature. Martin, R. Bruce. J. Chem. Educ.1999, 76, 1081.

Consumer Chemistry |

Gases |

Nonmajor Courses |

Water / Water Chemistry |

Atmospheric Chemistry

The Persistence of the Candle-and-Cylinder MisconceptionJames P. Birk and Anton E. LawsonThere is a persistent misconception that when a lighted candle is supported in a container of water and a closed cylinder is lowered over the candle, the candle is extinguished after a time by complete consumption of the oxygen in the cylinder, with a volume change corresponding to the amount of oxygen in the air. This misconception has appeared in the literature periodically for many years. Here, we present a number of experiments that refute this misconception.Birk, James P.; Lawson, Anton E. J. Chem. Educ.1999, 76, 914.

Thermal Physics (and Some Chemistry) of the AtmosphereStephen K. LowerAn exploration of how the temperature of the atmosphere varies with altitude can serve as a useful means of illustrating some important principles relating to the behavior of gases and to the absorption and transformation of radiant energy. Lower, Stephen K. J. Chem. Educ.1998, 75, 837.

Atmospheric Chemistry |

Gases

Saving Your Students' Skin. Undergraduate Experiments that Probe UV Protection by Sunscreens and SunglassesJames R. Abney and Bethe A. ScalettarThis article describes absorption spectroscopy experiments that illustrate the mechanism of action of sunscreens and sunglasses and that highlight the differences between different products. The experiments are well suited to incorporation into an undergraduate science laboratory and will expose students to absorption phenomena in a familiar context with substantial environmental and medical relevance. Abney, James R.; Scalettar, Bethe A. J. Chem. Educ.1998, 75, 757.

Photochemistry |

UV-Vis Spectroscopy |

Atmospheric Chemistry |

Applications of Chemistry |

Spectroscopy

Photocatalytic Degradation of a Gaseous Organic PollutantJimmy C. Yu and Linda Y. L. ChanA simple and effective method to demonstrate the phenomenon of photocatalytic degradation of a gaseous organic pollutant was developed. Titanium dioxide (anatase) was used as the photocatalyst, and sunlight was found to be an effective light source for the activation of TiO2. The organic pollutant degrade in this demonstration was a common indoor air pollutant, dichloromethane.Yu, Jimmy C.; Chan, Linda Y. L. J. Chem. Educ.1998, 75, 750.

Catalysis |

Photochemistry |

Atmospheric Chemistry |

Applications of Chemistry

Chemical BehaviorPaul G. JasienIn order to increase student understanding of the seemingly confusing behavior of chemical substances involved in environmental chemistry, an analogy between chemical and human behavior is presented. The analogy focuses on how the same individual can behave differently due to his/her social surroundings.Jasien, Paul G. J. Chem. Educ.1997, 74, 943.

Molecular Properties / Structure |

Nonmajor Courses |

Consumer Chemistry |

Atmospheric Chemistry

A Simple and Low-Cost Air SamplerSashi Saxena Ratna and Pramrod UpadhyayIn this article, an air sampler kit is presented that can be assembled from locally available household materials. The reliability of the sampler kit is also established.Ratna, Shashi Saxena; Upadhyay, Pramod. J. Chem. Educ.1996, 73, 787.

Atmospheric Chemistry |

Laboratory Equipment / Apparatus |

Quantitative Analysis

The Environmental Chemistry of Trace Atmospheric GasesWilliam C. TroglerInformation regarding the composition of trace gases in the Earth's atmosphere, changes in these amounts, their sources, and potential future impact on the environment.Trogler, William C. J. Chem. Educ.1995, 72, 973.

A new use for the candle and tumbler mythPeckham, Gavin D.In the time it takes to complete the popular but lengthy steel-wool experiment, this author proposes an activity that can be done to add an extra dimension to analyzing oxygen content. This combination of "good" and "bad" experiments proves to be a powerful pedagogical tool.Peckham, Gavin D. J. Chem. Educ.1993, 70, 1008.

The absorption of UV light by ozone Koubek, EdwardUsing a low-pressure mercury vapor UV lamp and a recently laundered white cotton sheet as a background, one can produce a shadowgraph of ozone emerging from an ozonator.Koubek, Edward J. Chem. Educ.1989, 66, 338.

Development of intellectual skills in the laboratoryOphardt, Charles E.This first semester laboratory was designed to give instruction and practice in the intellectual skills of application, analysis, synthesis, and in Piaget's formal operations.Ophardt, Charles E. J. Chem. Educ.1978, 55, 485.

Great spray can debateBassow, HerbA curriculum scenario that takes the problems raised by the technological, economic, and political contexts of the fluorocarbon controversy as its point of focus.Bassow, Herb J. Chem. Educ.1977, 54, 371.

Cloud Caps on High MountainsStevenson, Philip E.The formation of cloud caps on high mountains illustrates cooling in an adiabatic expansion and the change in vapor pressure of a liquid with temperature.Stevenson, Philip E. J. Chem. Educ.1970, 47, 272.

Atmospheric Chemistry |

Gases |

Applications of Chemistry |

Phases / Phase Transitions / Diagrams |

Thermodynamics

Environmental chemistry in the classroomDay, Jean W.The environmental sciences is an especially good vehicle for relating chemistry to other disciplines in courses for nonscientists.Day, Jean W. J. Chem. Educ.1970, 47, 260.

Nonmajor Courses |

Atmospheric Chemistry |

Applications of Chemistry

Stable isotopes of the atmosphereEck, C. F.This article briefly presents the composition of air, the discovery of isotopes, their concentration in air, and reviews their current enrichment status.Eck, C. F. J. Chem. Educ.1969, 46, 706.

Demonstration notes: Oxygen in airGlanz, JosephExplains that the popular method of demonstrating the percentage volume of oxygen in air is fraut with errors.Glanz, Joseph J. Chem. Educ.1963, 40, A477.

Gases |

Atmospheric Chemistry

Radioisotopes on your rooftopLockhart, Luther, B., Jr.The collection, recovery, and measurement of radioactive materials from atomic testing can be done through the use of relatively simple procedures and is a good exercise in tracer chemistry.Lockhart, Luther, B., Jr. J. Chem. Educ.1957, 34, 602.

Nuclear / Radiochemistry |

Atmospheric Chemistry |

Isotopes

Letters to the editorWolf, Milton G.The author offers a means of determining the percentage composition of oxygen in air through burning phosphorus.Wolf, Milton G. J. Chem. Educ.1956, 33, 148.